Male sex steroids are responsible for depressing macrophage immune function after trauma-hemorrhage.

Recent studies suggest beneficial effects of castration before soft tissue trauma and hemorrhagic shock on splenocyte immune functions. Nonetheless, it remains unknown whether this effect of testosterone depletion is limited to splenocytes or is a generalized effect on immune function. The present study was therefore carried out to determine whether androgen depletion before trauma-hemorrhage also has salutary effects on splenic and peritoneal macrophage as well as on Kupffer cell function, as indicated by interleukin (IL)-1 and IL-6 release. Male C3H/HeN mice were castrated or sham-castrated 2 wk before the experiment and were killed at 24 h after trauma-hemorrhage and resuscitation. Significant depression of macrophage IL-1 and IL-6 release was only observed in sham-castrated mice, as opposed to normal levels of cytokine release from castrated animals after trauma-hemorrhage. In addition, only sham-castrated animals showed significantly increased levels of IL-6 release from Kupffer cells, which is believed to contribute to the systemic inflammatory response to trauma-hemorrhage. These observations suggest that the beneficial effects of androgen depletion before trauma-hemorrhage are not limited to splenocyte immune functions but are more global in nature. These results in surgically castrated animals suggest that androgen-blocking agents should be studied for their potential to reverse the immunodepression associated with trauma-hemorrhage.